| 초록 |
The electronic and microelectronic industry requires lower dielectric constant material because of many problems in circuit performance, such as signal transmission rates and power dissipation. In this study, the supercritical CO2 technology was applied to effectively functionalize organic/inorganic hybrid materials. In this approach, we have studied novel process for hybridization of polyimide/silsesquioxane with porous inner structure. At first, polyimide precursors were synthesized with 4,4'-methylenebis(phenyl isocyanates) (MDI) and 4,4'-(hexafluoroisopropylidene)diphthalic anhydrides (6-FDA). And then polyimide precursors were reacted with 3-aminopropyltrimethoxysilanes (APMS) to terminate the end group of them by silyl groups of APMS. Methyltriethoxysilanes (MTES) were introduced for hybridization by the condensation reaction with silyl end groups of polyimide precursors and ethoxy groups of MTES via sol ?gel process in supercritical CO2. MTES could be cured into methylsilsesquioxanes and polyimide precursors were imidized by varying the temperature and pressure of supercritical CO2. Porous structure was obtained by utilizing supercritical CO2 and by-product CO2, which derived form 6-FDA with MDI. The hybrid polyimide/silsesquioxane with porous structure were characterized their chemical composition, thermal properties and morphology. |
